The present disclosure relates to photovoltaic devices, and more particularly to photovoltaic devices such as, for example, solar cells.
A photovoltaic device is a device that converts the energy of incident photons to electromotive force (e.m.f.). Typical photovoltaic devices include solar cells, which are configured to convert the energy in the electromagnetic radiation from the Sun to electric energy. Multi-junction solar cells of different semiconductor compositions may be employed for power generation in space due to their high efficiency and radiation stability. Multi-junction solar cells are mainly fabricated on germanium (Ge) substrates due to the inherently strong (IR) absorption property of germanium (Ge). Germanium (Ge) also includes a crystal structure that can be lattice matched to III-V materials, which allows for integration of III-V sub cells on a germanium (Ge) substrate. The germanium (Ge) substrate may constitute nearly 50% to 70% of the final cost of the finished solar cell.